Introducing a bottle or making the switch from breastfeeding to bottle feeding is actually surprisingly difficult for a lot of babies - and telling them that their formula-fed friends have been doing this for months isn't usually much help. For every child who loves her bottle so much she won't give it up for big-kid cups and plates, there’s another who won’t start on the bottle to begin with.
Some breastfeeding advocacy groups and organizations, like the La Leche League, or the Sears family, argue that nipple confusion could be why a baby will cling to your breast instead of reaching for a bottle when it’s offered. Nipple confusion is the idea that the physical process of sucking on a bottle is different enough from sucking on a breast that it’s not always a transferable skill. While the World Health Organization’s guidelines for breastfeeding back up the idea of nipple confusion, though, it isn’t a universally accepted theory.
Another reason your baby could decide not to accept a bottle-nipple, either out of nowhere after months of successful bottle use or just out of hand when you first introduce it, is because she can - your baby has reached the point where she can make decisions, and when that happens, she often chooses the breast over the bottle. There's a good chance she prefers the physical closeness and snuggles of breastfeeding, as well as the growing awareness that she has the power to refuse things. In fact, one of the most popular pieces of advice for how to coax a reluctant baby towards the bottle is to have it fed to her by someone other than her mother, to the point where she might have to leave the room or even the house, so your baby doesn’t feel like she is settling for the bottle when fresh breast milk is just across the room away from her.
There’s a lot of advice out there about how to convince your reluctant little one that the bottle is the way to go, at least during work hours, and a lot of the techniques involve trying to mimic the breastfeeding experience, from finding bottle nipples that mimic the shape of yours to other caregiver wearing your clothes so they smell like you to your baby. On the other hand, some techniques suggest going in the opposite direction, where your baby is fed in a completely different position from breastfeeding. This would involve a differently shaped bottle and nipple, so that she will accept bottle feeding as a completely different type of feeding, instead of a pale imitation.
Babies who reject bottle feeding can often be convinced to give it a shot eventually. What’s evident about the ways you can try to make that happen is that the bottle rejection, more than anything, is generally about the way your baby misses being close to you when she eats. If you’re having trouble convincing her to settle for a less-loved bottle, though, consider trying to make the jump straight from breast to sippy or other small plastic cup.